Sound-box.



P. DODGE.

souNu Box;

APPLICATION FILED MAYIB, 1915.

Patented De.'25,1917.

lfb I i UNITED STATES PATENT OFFICE.

PARKER DODGE, or WASHINGTON; ms'rmc'ry or commun SOUND-noi;

specmeationof Letters Patent: Paih'td'i Dec425`; 1917# ingis a specification.

his invention relates to sound boxes'for gramophoue's, graphophones and the like and the principal features of novelty reside in the mounting of the diaphragm. The invention has a special Yutility and function when combined with -the character? isti c' features of thel sound 'box described and claimedin my copendingapplication Serial Number 12,578; filed March '6; 1915. Accordingly, in order t'o disclose'. the best em'- bodiment ltno'n'nfto me, andtofpermit the making-of specific claims to 'that cmbin'a.- tion, I'he'reinaftr describey the invention: as appliedtothe structure of my said a' plie-.a1 tion. I do not, howe'vi, limit 'm'ysl there; t,.as'. certain advanta`ge's of the inyentin may be secured witlr other sourifdboxesf in which the diaphragm isrigidly' mounted.v The :intention consists in` a soi1ndv box in which tlie'diaplfra'vm rigidlymounted and held under a uniormly 4distributed lradial compressive stress acting in the plane of the diaphragm. A diaphragm Vso 4mounted is peculiarly inert and devoid of inherent, reso? nance; it vibrates freely with a relat'iiely wide amplitude, giving an increased volume und roundness of tone, and an increased response to sibilants and breathy sounds.

I shall non" describe the invention as apf lied to a gramophonic reproducer,in whic l1 1t has been successfully used. Those skilled in the art will appreciate its applicability to other types of reproducer and to recorders by the making of siniple substitutions well knoivn in the art.

Referring to the drawings: Figure 1 is a front elevation of a sound box having my invention applied;

Fig. 2 is an axialsec'tion thereof; Fig. 3 isan enlarged fragmentary View similar to Fig. 2;

Fig. lisa perspective view ofa diaphragm clamping ring of preferred form, apart of the ring being shown broken away to clearly show ythe form; and

Fig. 5 is an elevation of a diaphragm with the stresses to which it is subjected diagram? maticallyindicated.

In. the drawings- 6 represents the usual in lugs Q3 and locked with check nuts'24 It. has the usual needle socket in which needles may be clamped by the set screw 25. The stylus arm 21 is connected to the center of the diaphragm 15 by means of a threadedf stud 26 and nut 27, the usual washers 28 being used to distribute the pressure.

The structure so far described forms the subject matter of my application above identified and consequently is not broadly claimed herein.

To apply my invention to such a sound box, it is necessary simply to clamp the diaphragm 15 between the rings 1G and 17 in such a way that it will be held by them under a radially acting compressive stress. Any preferred method of securing this result may be adopted. One convenient method is loosely to assemble the diaphragm 15, clamping rings 16 and 17, washers 2() and nut ring 19 in the box-body 9, then to deflect the diaphragm an amount approximating` the maximum deflection of the diaphragm desired in reproducing from records, and finally while holding the diaphragm so deflected to set up the nut ring- 19 until the periphery of the diaphragm is clamped fast'between the rings 16 and 17. This holds the periphery in the contracted state rcsulting'from the deflection of the diaphragm. This method forms a part of the subject matter of my copending application, Serial Number 28,910, filedvMay 18, 1915,l and 'hence is not claimed herein.

`In Fig. 5 I illustrate diagrammatically the diaphragm and the stresses to which it is subjected. The arrows are intended to illustrate by their close spacing a uniformly distributed stress acting radially at all points around the periphery or line of clamping of the diaphragm The imparting of this compressive stress to a rigidly mounteddiaphragm seems invariably to increase the roundness and loudness of the tone produced by such diaphragm, and renders certain sounds such as sibilants clearly audible. The increased sensitiveness of the diaphragm, vwhen so stressed, increases the tendency to whine and blast under some conditions, but I have found that the use of the conoidally recessed rings of my prior application completely neutralizes this effect. Furthermore the stressed diaphragm when applied to the sound box of my prior application markedly increases the range of records which may be reproduced therewith.

Thus the invention resides first in the stressed diaphragm, and second in the comf bination of this with clamping 'means having conoidally recessed proximate clamping faces. Different methods and means for securing the stressing and different mechanical expressions of the clamping members, etc., are possible, are contemplated and fall within the scope of the invention. The clamping members may be made of materials of different degress of resiliency, provided they are substantially rigid.

Having thus described the invention what I cla-im is 1. In a sound box, the combination of a box body; a vibrator mechanism; a substantially rigid support for the peripheral portion of a' diaphragm, carried by said box body; and a flexible diaphragm held by said support in a state of radial compression, and operatively connected with said vibrator mechanism.

2. In a sound box, the combination of a box body; a vibrator mechanism; a substantially rigid support engaging the peripheral portion of a diaphragm and carried 'by said box body; and a mica diaphragm held by said support in a state of radial compression, vand operatively connected with said vibrator mechanism.

Ina sound box, the combination of a box body; a vibrator mechanism; relatively rigid'clamping means mounted in said box body for exertinga clamping action upon the faces of a diaphragm at or near its periphe and a flexible diaphragm held 'by said ei'amping means in a state of radial compression, and operatively connected with said vibrator mechanism.

' 4i In a sound box, the combination of a box body; a vibrator mechanism; celluloid clamping means mounted in said box body for exerting 'a clamping action upon the faces of avd1aphragzm at or near its eriphery; and a flexible diaphragm held y said clamping means in a state of radial compression, and operatively connected with said vibrator mechanism. Y

5. In a sound box, the combination of' a. box body; a vibrator mechanism; clampinP means of relatively ,rigid material mounted in said box-body and formed with opposed conoidally recessed clamping faces for receiving an interposed diaphragm, said faces being so formed as each to have an annular area of contact with the proximate face of such diaphragm at or near the periphery thereof, and to curve gradually away from said diaphragm toward the center; and a diaphragm held by said clamping means in a state of radial compression, and operatively connected With said vibrator mechamsm.

6. In a sound box, the combination of a box body; a vibrator mechanism; clamping means of relatively rigid but elastic material mounted in said box body and formed with opposed conoidally recessed clamping faces for receiving an interposed diaphragm, said faces being so formed as each to have an annular area of contact with the proximate face of such diaphragm at'or near the periphery thereof, and to curve gradually away from said diaphragm tovcompression, and; operatively fwlth saldA vibratorfymechamsm.

l Itei-posed diaphragm, said. `faces being so i @jformedas leachfto have an annular'area'off..

contact'pwith the proximateface ofsuch" diaphragm `at or near the periphery thereof, and to' curve gradually awayfrom said diaphragm held by said clampin vmeans in a.`

,Connectedwithsaid vibrator mechunismff i' 8. Ina sound boxl the combination ofl'a 20 l' p annular diaphragmfsupporting area'mer ing intoa central recesswhich dures gra i uallyaway fromftheface of the''eupportedy ward the center; and a diaphragm held by said clampingmea'ns in -a stateof `radial connected` ce, e 1 ''.In a sound box,l the combination of,k a]v boi: bod-y;l a Ivibrator mechanism; clam ingl means of celluloid mounted injsaidv box ody] y .e `and "formed `with opposed con `o'ida1 1y re-f tossed` clamping faces for receiving an in?` phr'agmv toward the centers;` and endian-p *statevofradial compression, an operatively "relatively rigid diaphragm mount havingany y* diaphragmtowardy the` centerymeans iol; `iclampingtheyperiphery of'a diaphragmy ,-"against said tm'ountya flexible diaphragm heldby 'said' clamping means` inl a. state kofgy radial` compression l;. and a suitable` vibratoi-v f i mechanismffforl' said diaphragm;`

,. 9.111` ity sound` box `the combination a" relatively rigid diaphragmxmounthaving an j annular" diaphragm slipportin'g areamer-` i l kinginto. `a .central recess fwhch'flaresfgra n ually `away .from *the "face v'ofthe lsul'oported rdiaphragm toward 'the oenfter" a-second diaf `phgragm mountfhaving asur ftion` similarto-,thatof the Erst diaphragm mount; means for rforcing saidmouts togetherf;` a ieiiible diaphragm held betweeii, i "i" `said mounts -in a State ofv radiabcompresj-f. v v sion; andra* suitable vibrator mechanism for"" i saiddiaphragm.` e 4 e In testimony whereof I have name `to this specificationgl l' v .c

mi Ipolaca..

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